1. Field of the Invention
The present invention relates to the seating or other positioning of operators within vehicles, and more particularly to the positioning of an operator within the cab of a tractor or similar vehicle which can undergo substantial motion for optimum operator visibility and comfort.
2. History of the Prior Art
Vehicles designed principally for off-road use such as agricultural tractors have the potential of subjecting the operator thereof to substantial amounts of unpleasant motion because of the rough terrain which such vehicles must typically negotiate. In addition to some vibration, such vehicles sometimes subject the operator to constant pitching and jolting motions. The resulting operator fatigue can be a significant if not serious problem when it is considered that the operator typically operates such vehicles for extended time periods.
As a consequence, it has become commonplace to mount the operator seat in a tractor or other vehicle which undergoes substantial motion using a suspension of the type which permits attenuated motion. In addition, seats in vehicles of this type are often provided with various adjustments including the capability of swiveling so as to enhance operator comfort and convenience. Examples of such prior art seats are provided by U.S. Pat. Nos. 4,195,883, 4,128,217, 3,917,210, 3,922,030, 4,062,588, 3,999,800 and 4,099,777.
In addition to providing a movable seat suspension to minimize the effects of shocks and other undesirable motions, it is necessary to be able to position the seat relative to the various controls such as the steering wheel and foot pedals so that the operator can comfortably and confidently operate such controls. This is typically accomplished by making the seat both height-adjustable and adjustable in the fore-aft direction relative to the controls which are fixedly mounted to the interior of the cab of the vehicle. Such adjustments typically enable the operator to assume a convenient, comfortable position relative to the steering wheel, foot pedals and other controls, but often at the expense of good visibility from the cab. For example, the operator who is much taller than average must typically raise the height of the seat to properly position his feet relative to the foot pedals which are mounted at a fixed location on the cab floor. This may result in the operator being positioned high enough within the cab so as to seriously impair the operator's upward view and possibly even his view straight ahead from the cab. The smaller than average operator, on the other hand, tends to lower the height of the seat so as to bring his feet within a comfortable distance of the foot pedals, thereby impairing the operator's downward vision from the cab. In the case of either the tall operator or the smaller than average operator, adjustment of the seat height and fore-aft position to optimize control and comfort with respect to the foot pedals can result in certain other controls being awkward or inconveniently located.
Aside from the visibility problems noted, conventional seating and control arrangements may produce considerable operator fatigue despite the use of attenuated seat suspensions because of relative motion between the seat and thereby the operator who is positioned within the seat and the various controls which are typically mounted on or coupled to the fixed interior of the cab. As the vehicle undergoes vibration, shaking or other motion in response to uneven terrain and the like, the resulting movement of the seat may produce considerable motion between the operator and such things as the foot pedals, steering wheel and other controls. This relative motion is not only fatiguing but can result in sufficient loss of control so as to become a safety factor in some instances.
In an effort to provide improvement in seating accommodations for off-road vehicles and for other applications, a variety of different arrangements have been proposed. In one such arrangement shown in U.S. Pat. No. 3,357,717 of Samford, the seat and steering column assembly are both mounted on an integral platform which in turn is coupled to the flooring therebelow by arrangements of springs or other resilient elements. The seat is adjustable in the fore-aft direction, and the steering column assembly is tiltable and telescoping. In U.S. Pat. No. 4,059,171 of Pakosh, the steering column assembly and seat are also mounted on a common flat platform. The platform is coupled to the floor therebelow through a swivel and a fore-aft adjustment so that the entire platform can be rotated 180.degree. to facilitate operation of the vehicle in opposite directions. U.S. Pat. No. 4,200,166 of Hansen and U.S. Pat. No. 4,026,379 of Dunn et al show seating arrangements in which some of the controls are incorporated into an armrest or console positioned adjacent the arm of the seat. U.S. Pat. No. 4,194,716 of Barecki et al shows a common seating arrangement for various types of vehicles in which the seat is mounted to the floor therebelow through an attenuating arrangement, a fore-aft adjustment mechanism and a scissors-type vertical height adjustment. U.S. Pat. No. 4,008,500, British Patent Specification No. 1,185,848 and German Pat. No. 1,932,955 show still other seating arrangements designed to fulfill various requirements.
None of the seating arrangements of the prior art including those shown in the above patents address the basic problem of optimizing the location of the operator within the cab for maximum visibility while at the same time optimizing operator comfort through not only attenuated, limited movement of the seat but at the same time minimization of motion of the controls relative to the operator.
Accordingly, it is an object of the invention to provide an improved operator station within a cab for agricultural tractors and similar vehicles.
It is a further object of the invention to provide an improved operator's station which optimizes the position of the operator for maximum visibility while at the same time providing comfort through controlled resistance to undesirable motion.
It is a further object of the invention to provide an improved operator's station within a cab which not only optimizes the viewing position of the operator but at the same time minimizes unwanted, fatiguing motion of the controls relative to the operator.